Geochemical approaches for cryosphere studies on glacial-interglacial timescales

地球系统正处于一种类似于过去数百万年来最热时期的气候状态，而这种变暖的影响在北方已经很明显。在很大程度上，气候变化对北方环境的影响因涉及冰冻圈--冰川、冰盖、永久冻土和海冰--的反馈而加剧。拟议的研究计划将使用地球化学研究工具来解决以下首要问题：在过去100,000年来持续的气候变暖期间，北极冰冻圈的元素(如冰盖、冰川和永久冻土)是如何反应的，反过来，这些反应又如何反馈到海平面上升、碳循环和区域水文变化等地球系统过程中？ 拟议的研究计划包括三个准独立的线索，共同解决这些首要问题。这些专题将涉及以下主题：(1)格陵兰冰盖退缩和气候变暖持续期间的相关地貌变化；(2)在地貌尺度上确定过去持续变暖期间永久冻土退化的程度；(3)冰冻圈变化对北部地貌和地球系统过程的间接影响。 这项研究计划将为重要的科学和社会问题提供新的方法和重要的见解。我提议研究的间冰期可能是最容易获得的地质学类比，可以预测下个世纪北极变暖的地貌和地球系统过程将是什么样子。考虑到广泛的多年冻土融化所固有的潜在的碳循环反馈和基础设施方面的挑战，拟议的关于过去温暖时段的多年冻土响应的研究结果将引起科学和公众的广泛兴趣。考虑到对当代格陵兰冰盖行为的重大科学兴趣，以及对评估其对未来海平面上升的潜在贡献的迫切公众兴趣，对过去持续变暖期间格陵兰冰盖消退的研究也将产生非常重要的结论。

The earth system is on a trajectory towards a climate state that is similar to the warmest intervals of the last several million years, and the impacts of this warming are already apparent in the north. In large part, the impacts of climate change in northern environments are exacerbated by feedbacks involving the cryosphere – glaciers, ice sheets, permafrost, and sea ice. The proposed research program will use geochemical research tools to address the following overarching questions: how did elements of the arctic cryosphere (e.g. ice-sheets, glaciers, and permafrost) respond during periods of sustained climate warming over the last several 100,000 years and, in turn, how did these responses feed back into earth-system processes like sea-level rise, carbon cycling, and regional hydrological change? The proposed research program includes three quasi-independent strands that collectively tackle these overarching question. These strands will address the following themes: (1) Greenland ice-sheet retreat and associated landscape change during sustained intervals of climate warming; (2) developing methods to determine, on a landscape-scale, the extent of permafrost degradation during sustained past warm intervals; and, (3) indirect impacts of cryospheric change on northern landscapes and earth-system processes. This research program will provide new approaches and important insights into important scientific and societal questions. The interglacial periods I propose to study are perhaps the most accessible geological analogues for what landscapes and earth-system processes will be like in the warmer Arctic that is projected for the coming century. There will be wide scientific and public interest in the results of the proposed research on permafrost response through past warm intervals, given the potential carbon cycle feedbacks and infrastructural challenges inherent in widespread permafrost thaw. Research on Greenland ice-sheet retreat during past sustained warm intervals will also yield highly significant conclusions, given the substantial scientific interest in contemporary Greenland ice-sheet behaviour and the compelling public interest in assessing its potential contribution to future sea-level rise.